Commit 1984c805 authored by Leonardo Bras's avatar Leonardo Bras Committed by Catalin Marinas
Browse files

arm64: remove unnecessary ifdefs around is_compat_task() 



Currently some parts of the codebase will test for CONFIG_COMPAT before
testing is_compat_task().

is_compat_task() is a inlined function only present on CONFIG_COMPAT.
On the other hand, for !CONFIG_COMPAT, we have in linux/compat.h:

 #define is_compat_task() (0)

Since we have this define available in every usage of is_compat_task() for
!CONFIG_COMPAT, it's unnecessary to keep the ifdefs, since the compiler is
smart enough to optimize-out those snippets on CONFIG_COMPAT=n

This requires some regset code as well as a few other defines to be made
available on !CONFIG_COMPAT, so some symbols can get resolved before
getting optimized-out.

Signed-off-by: default avatarLeonardo Bras <leobras@redhat.com>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240109034651.478462-2-leobras@redhat.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent a743f26d

arch/arm64/include/asm/elf.h

+5 −5
Original line number Diff line number Diff line
@@ -201,16 +201,16 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm, 
#define COMPAT_ELF_PLATFORM		("v8l")

#endif



#ifdef CONFIG_COMPAT



/* PIE load location for compat arm. Must match ARM ELF_ET_DYN_BASE. */

#define COMPAT_ELF_ET_DYN_BASE		0x000400000UL



/* AArch32 registers. */

#define COMPAT_ELF_NGREG		18

typedef unsigned int			compat_elf_greg_t;

typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_ELF_NGREG];



#ifdef CONFIG_COMPAT



/* PIE load location for compat arm. Must match ARM ELF_ET_DYN_BASE. */

#define COMPAT_ELF_ET_DYN_BASE		0x000400000UL



/* AArch32 EABI. */

#define EF_ARM_EABI_MASK		0xff000000

int compat_elf_check_arch(const struct elf32_hdr *);

arch/arm64/include/asm/fpsimd.h

+0 −2
Original line number Diff line number Diff line
@@ -21,7 +21,6 @@ 
#include <linux/stddef.h>

#include <linux/types.h>



#ifdef CONFIG_COMPAT

/* Masks for extracting the FPSR and FPCR from the FPSCR */

#define VFP_FPSCR_STAT_MASK	0xf800009f

#define VFP_FPSCR_CTRL_MASK	0x07f79f00
@@ -30,7 +29,6 @@ 
 * control/status register.

 */

#define VFP_STATE_SIZE		((32 * 8) + 4)

#endif



static inline unsigned long cpacr_save_enable_kernel_sve(void)

{

arch/arm64/kernel/ptrace.c

+3 −5
Original line number Diff line number Diff line
@@ -174,7 +174,6 @@ static void ptrace_hbptriggered(struct perf_event *bp, 
	struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);

	const char *desc = "Hardware breakpoint trap (ptrace)";



#ifdef CONFIG_COMPAT

	if (is_compat_task()) {

		int si_errno = 0;

		int i;
@@ -196,7 +195,7 @@ static void ptrace_hbptriggered(struct perf_event *bp, 
						  desc);

		return;

	}

#endif



	arm64_force_sig_fault(SIGTRAP, TRAP_HWBKPT, bkpt->trigger, desc);

}
@@ -1596,7 +1595,6 @@ static const struct user_regset_view user_aarch64_view = { 
	.regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)

};



#ifdef CONFIG_COMPAT

enum compat_regset {

	REGSET_COMPAT_GPR,

	REGSET_COMPAT_VFP,
@@ -1853,6 +1851,7 @@ static const struct user_regset_view user_aarch32_ptrace_view = { 
	.regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)

};



#ifdef CONFIG_COMPAT

static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,

				   compat_ulong_t __user *ret)

{
@@ -2114,7 +2113,6 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, 


const struct user_regset_view *task_user_regset_view(struct task_struct *task)

{

#ifdef CONFIG_COMPAT

	/*

	 * Core dumping of 32-bit tasks or compat ptrace requests must use the

	 * user_aarch32_view compatible with arm32. Native ptrace requests on
@@ -2125,7 +2123,7 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) 
		return &user_aarch32_view;

	else if (is_compat_thread(task_thread_info(task)))

		return &user_aarch32_ptrace_view;

#endif



	return &user_aarch64_view;

}

arch/arm64/kernel/syscall.c

+1 −4
Original line number Diff line number Diff line
@@ -20,14 +20,11 @@ long sys_ni_syscall(void); 


static long do_ni_syscall(struct pt_regs *regs, int scno)

{

#ifdef CONFIG_COMPAT

	long ret;

	if (is_compat_task()) {

		ret = compat_arm_syscall(regs, scno);

		long ret = compat_arm_syscall(regs, scno);

		if (ret != -ENOSYS)

			return ret;

	}

#endif



	return sys_ni_syscall();

}